[centex]

Welcome to the forum.

Is this an "S" with (electric release) manual liftgate or do you have the power liftgate?

For manual liftgate:

• After ensuring that the car is fully unlocked (double-press on the unlock button on the driver's door) try firmly 'tugging' while pressing the button in the liftgate handle.
• If you think it's not releasing the electric lock, check the fuse in your BCM (10A F65 in 2014, might be different in your 2017, see fuse list in your owner's manual).

For power liftgate, in addition to above:

• As long as it will unlock you can open the gate manually even if the power-lift is inoperative, just takes a very firm manual lifting force.
• The power-lift fuse is 25A F25 in the rear fuse box (again may be different for '17, check owner's manual). Yeah, you'll have to crawl from the front if you can't get the gate open.

I've had a couple of occasions where my power liftgate gasket 'sticks' preventing the gate from opening itself - the 'tug while pressing the button' breaks it loose then all is good (wipe the gasket clean and dry).

There's always the dealer, your '17 still in-warranty (100 miles total or since you got it used) ?